This paper presents the results of a thermo-economic analysis of integrating solar tower (ST) with heat and power cogeneration plants that is progressively being installed to produce heat and electricity to operate absorption refrigeration systems or steam for industrial processes. The annual performance of an integrated solar-tower gas-turbine-cogeneration power plant (ISTGCPP) with different sizes of gas turbine and solar collector's area have been examined and presented. Thermoflex + PEACE software's were used to thermodynamically and economically assess different integration configurations of the ISTGCPP. The optimal integrated solar field size has been identified and the pertinent reduction in CO2 emissions due to integrating the ST system is estimated. For the considered cogeneration plant (that is required to produce 81.44 kg/s of steam at 394 °C and 45.88 bars), the study revealed that (ISTGCPP) with gas turbine of electric power generation capacity less than 50 MWe capacities have more economic feasibility for integrating solar energy. The levelized electricity cost (LEC) for the (ISTGCPP) varied between $0.067 and $0.069/kWh for gas turbine of electric power generation capacity less than 50 MWe. Moreover, the study demonstrated that (ISTGCPP) has more economic feasibility than a stand-alone ST power plant; the LEC for ISTGCPP is reduced by 50–60% relative to the stand-alone ST power plant. Moreover, a conceptual procedure to identify the optimal configuration of the ISTGCPP has been developed and presented in this paper.